Actively seeking HF antenna...

[GlynH]

Hi there,

I am looking for the 'best' HF antenna for use with my WiNRADiO G313

I realise this is a loaded question so I shall rephrase the above by saying I am looking for an active antenna that would best suit my needs.

A long wire would certainly be the cheapest solution but not necessarily the best and would not be easy to setup not to mention the mess of wires reaching across my garden!

I had originally thought the WiNRADiO AX-81S would be a good match but from doing some research I see the Wellbrook Active Loop ALA1530 series seems to get good reviews.

A friend of mine who knows about these things also suggested I should look at the Dressler offering.

Has anyone out there been down this road before or have experience of one or the other or maybe without confusing me and making my choise harder than it already is suggest an alternative?

If it has any bearing I am @500ft asl and have always enjoyed great TV & Radio reception from my QTH.

It would be great to give my G313 the HF antenna it deserves rather than temporarily using the Royal Discone that is usually attached to my G305!

Thanks & kind regards,
-=Glyn=-

 

[ka3jjz]

Both Wellbrook and Dressler have outstanding reputations, but if I had to choose, I'd choose the Wellbrook loop in a heartbeat. I know a couple of NASWA members have them, and I've heard nothing but great comments about them.

Something to consider - loops are less prone to certain kinds of electrical interference (depending on the local RF environment), so if you're in an urban or semi urban environment, it's something else to consider. I don't believe Dressler markets an amplified loop (I could be wrong - it's been years since I've even heard about them...).

It's expensive but if I could swing it, I wouldn't hesitate....73 Mike

 

[kb5udf]

G5rv

I would suggest consideration of the humble G5RV. It can be deployed in a variety of configurations, and has a wide bandwidth per design.

This IMHO is one of the better very low cost options.

If your budget is far larger, and depending on your frequency range needs, you might consider a tower mounted beam at about 55 feet.

Options here might include some of the very large log periodics or newer tech like the StepIR, which is continuously tunable, I think between about 7-30, mhz.

In summary G5RV = cheap, jack of all trades, wide bandwidth by design
Various HF beams = pricey, but potentially very effective for weak signals.

The relative elevation of your location, though important for VHF and up, is relatively unimportant for HF monitoring. However, the height of your antenna above ground IS very relevant at HF (but higher is not necessarily better).

JB

JB

 

[Turbo68]

I use a Wellbrook-ALA1530 Active Loop mainly monitor aero/utilities excellent hf antenna & there are a few rr members using the antenna.

Regards Lino.

 

[zz0468]

I would suggest consideration of the humble G5RV. It can be deployed in a variety of configurations, and has a wide bandwidth per design.

The G5RV isn't actually broadbanded. It works because it exhibits multiple resonances and, built correctly, those multiple resonances occur inside harmonically related ham bands.

A similar idea, an open-wire feed to a dipole can be used across a wider spectrum, but it requires the use of an antenna coupler. The G5RV uses a balun where it transitions to coax, and the feed-line length of the balanced line is critical. Use a coupler instead of the tuner, and it's usable across the entire HF spectrum, although the pattern gets pretty weird as you go up in frequency.

 

[ka3jjz]

The OT said he didn't want wires all over his garden - so let's keep to the topic of actives and loops.

Thanks...Mike

 

[GlynH]

Thanks for the replies guys,

My mind was as good as made up on the Wellbrook but a friend of mine threw a spanner in the works when he mentioned Dressler :lol:

Some further questions on the Wellbrook if I may;

I hear it has been designed to work @6 feet from the ground. Is it really the case it would work better that low rather than up on the roof?

I already have more than enough antennas on the roof but if the performance increase was worth it I would figure out a way to get it safely mounted up higher rather than lower. I allmost know the answer to this before I ask but would installing it in the loft compromise performance too much? I would never dream of mounting my other antennas there but Wellbrook do make a specific semi-flexible loft version...

Finally is it directional? By that I mean would it benefit greatly from a rotator or is it a reasonable omni?

Thanks again in advance.

Kind regards,
-=Glyn=-

 

[comsec1]

I just ordered a wellbrook ala1530, it takes a long time to arrive but from all the reviews it is supposed to be the best active loop. If other wellbrook users could post on how long it took to arrive to the states that would be great. currently I use a B&W end feed V, and hustler 5BTV with the 60 meter resonator at my home station and a Alpha Delta DX-CC at my work station. My work station is at a radio "quiet" area and any antenna is good but my home is surrounded by homes where everyone seems to have somekind of "noise" producing device. even my own home had to be silenced as the light dimmer on the china cabinet wiped out HF, problem was cured by placing an extension cord with a an on/off inline switch. again if any wellbrook users could advise on delivery time as I'm on my third week. Thanks

 

[Turbo68]

Hi Glyn when i ordered my Wellbrook=ALA1530 took around 3 weeks for delivery location australia and this is a photo how the wellbrook is mounted around 5 metres high on the alfresco outdoor around the same distance from radio room performance is excellent at this height when it was mounted 12 metres high on the house roof performance wasnt good due to 1100 metres of electrical cable in the house using belden-9913 coax cable will be putting rotator when the weather gets warmer.

Regards Lino.
ALINCO-DJX2000
AOR-3000,AOR-3000A,AOR-8200M3
GRE-PSR500
ICOM-RX7,ICOM-R3,ICOM-R20,ICOM-R75,ICOM-PCR1000,ICOM-PCR1500,ICOM-PCR2500
PALSTAR-R30A
REALISTIC-PRO2035
UNIDEN-245,UNIDEN-396,UNIDEN-780
YAESU-VX7R,YAESU-FT8800,YASU-VR500

 

[ka3jjz]

Thanks for the replies guys,

My mind was as good as made up on the Wellbrook but a friend of mine threw a spanner in the works when he mentioned Dressler :lol:

Some further questions on the Wellbrook if I may;

I hear it has been designed to work @6 feet from the ground. Is it really the case it would work better that low rather than up on the roof?

I already have more than enough antennas on the roof but if the performance increase was worth it I would figure out a way to get it safely mounted up higher rather than lower. I allmost know the answer to this before I ask but would installing it in the loft compromise performance too much? I would never dream of mounting my other antennas there but Wellbrook do make a specific semi-flexible loft version...

Finally is it directional? By that I mean would it benefit greatly from a rotator or is it a reasonable omni?

Thanks again in advance.

Kind regards,
-=Glyn=-

It's impossible to speculate on specifics re mounting the loop indoors, since everyone's installation is likely to be different; everything from the construction of the attic (sri, loft), the wiring inside and around it, the number of electrical appliances in the immediate vicinity - all of this and more can play a role. I would expect some loss in noise rejection and/or overall gain, but this is pure speculation on my part.

I'm sure that the suggestion about putting it up about 2 meters or so in the air is to reduce any possible ground effects as well as attempting to get the loop outside the ambient noise floor of the house and surroundings. I suspect you would need to do something similar if you were to mount it on the roof.

As to directionality - well that's a bit of a complicated question. Keep in mind that a typical HF signal will not arrive at your antenna from just one direction - it's likely to be several at once. What may happen, depending on the freq, time of day, solar activity and other factors, is that a signal whose strongest component is coming from the side of the loop is likely to be attenuated somewhat. Therefore, a lite duty TV rotor could be used to turn the loop toward the signal's path. A crude approximation of this effect would be 2 flashlights taped back to back so they radiate both forward and back. Anything coming from the sides of the flashlights would be harder to see in a very dark room than something approaching from the front.

73 Mike

 

[ka3jjz]

<had to take a phone call> Another couple of things re 'nulling'

- It may be possible to turn the loop so it is less responsive to a local noise source

- From what I have read, the higher in freq you go, the less the null, due to the path that the signal is taking. You will notice this on MW freqs a lot, but much less so on 11 mhz. I can confirm that just from playing around with a small amplified loop for a time. As you go higher in freq, the loop becomes more omni in nature.

73 Mike

 

[zz0468]

From what I have read, the higher in freq you go, the less the null, due to the path that the signal is taking. You will notice this on MW freqs a lot, but much less so on 11 mhz. I can confirm that just from playing around with a small amplified loop for a time. As you go higher in freq, the loop becomes more omni in nature.

It's called "antenna effect". A loop must be quite small in terms of wavelength, and as you go higher in frequency, it ceases to act like a loop. and behaves more and more like just a chunk of metal, which would lose the characteristic null that loops have.